A 25-year-old Gloucester man was arrested on suspicion of a firearms offence and assault and has been bailed to return to police on 20 December, pending further inquiries.
It’s the twelfth arrest in connection with the incident, which happened on Sunday 12 November and is believed to be linked to a drugs feud.
Four people have been charged in connection with the investigation.
Detective Sergeant Alistair Hammett said: “We want the public to be reassured that every effort is being made to trace everyone involved in the altercation.
“This latest arrest shows that we are still working hard on this case and doing everything we can to bring people to justice.
“We still need information though – either via 101 or anonymously via the independent Crimestoppers anonymously on 0800 555 111.”